Various types of personalizable integrated circuits and programmable integrated circuits are known in the art. Personalizable integrated circuits include gate arrays, such as laser programmable gate arrays, commonly known as LPGA devices, which are described, inter alia in the following U.S. Pat. Nos.: 4,924,287; 4,960,729; 4,933,738; 5,111,273; 5,260,597; 5,329,152; 5,565,758; 5,619,062; 5,679,967; 5,684,412; 5,751,165; 5,818,728. Devices of this type are personalized by etching or laser ablation of metal portions thereof.
There are also known field programmable gate arrays, commonly known as FPGA devices, programmable logic devices, commonly known as PLD devices as well as complex programmable logic devices, commonly known as CPLD devices. Devices of these type are programmable by application of electrical signals thereto.
It has been appreciated in the prior art that due to the relatively high silicon real estate requirements FPGA devices, they are not suitable for many high volume applications. It has therefore been proposed to design functional equivalents to specific programmed FPGA circuits. Such functional equivalents have been implemented in certain cases using conventional gate arrays. The following U.S. Patents show such implementations: U.S. Pat. Nos. 5,068,063; 5,526,278 & 5,550,839.